Very generally it is between the fifth and seventh weeks that positive symptoms of worms first appear. And duly recognizing the fact that the liability to infection is great, also that a large proportion of puppies suffer from the pests, breeders generally hold that all should be given worm medicine near the eighth week, whether or not they present suspicious signs.

Notwithstanding that the liability and danger are all that breeders assume, such an iron rule is open to objections. For instance, were the bitch the only one of her kind in a family, or had she no more than one or two mates, and none were quartered in kennels, but all had places by the kitchen fire, and there the whelping had occurred and she and her little ones had been kept until the weaning, then to apply this rule and dose for worms in the absence of symptoms would scarcely be advisable, for the chances are many that under such happy, cleanly conditions the puppies would not be infested, or if they were the number of worms would be too small to do great harm.

But, on the other hand, had the mother several mates, all were kept in kennels, and the whelping occurred in quarters which had been frequented by other dogs, then it would be far too much to expect that the puppies had escaped infection, and the rule in question could properly be applied.

Here it is well to consider briefly the various estimates put upon the danger of treatment for worms. Some hold that judiciously selected and wisely applied, such treatment can do no harm if it fails to do good. Others, however, believe it to be somewhat hazardous with young puppies, no matter its nature or how carefully administered. Those who hold to the first are right provided the patients have passed the eighth week; and those at the other extreme are also right if the little ones are under this age. That is, all who dose puppies under eight weeks of age run some risk of killing them, but with older puppies death from suitable vermifuges is scarcely likely to occur.

But while there is danger in dosing puppies that are not yet two months old, it is very slight, and if the medicines are wisely chosen and given in proper quantities, it is doubtful if there is any beyond that of intestinal stoppage. Even this is extremely rare, and never occurs unless the patient is harboring an immense number of worms; in which case the parasites are suddenly aroused into unusual activity and carried rapidly downward by the action of the bowels, until before the outlet is reached there is an accumulation of them which dams up the passage.

Now, this accident will scarcely happen except in very young puppies in which all the powers are low, and which are only capable of a slight expulsive effort, and even this is lessened by the pain excited by the unwonted activity of the worms when the medicine first reaches them; whereas older puppies, having much greater strength, would under such conditions expedite the removal of the worms by constant straining, and so prevent their massing.

Considering these simple facts, the conclusion is justified that worm medicines should not be given to puppies that have not reached the eighth week unless quite pronounced symptoms of worms have been manifested. Also, that instead of dosing all puppies as soon as, or shortly after, they have reached this age, exceptions should be made of little ones born of house pets and kept in clean quarters; in whom evidences of worms are never likely to be overlooked, since it is necessary to renew the lining of their basket or box several times daily, and mucous discharges or worms expelled must be at once noted.

But where puppies are born in kennels and these signs of worms are not likely to be detected promptly, to give a vermifuge soon after the eighth week would probably be advisable; and yet he whose puppies were thriving well and free from all signs of the pests would often be the gainer by waiting a week or two before applying the "worming treatment."

The first vermifuge to be given puppies is wormseed oil; and this failing, santonin should be tried.

It occurs here that there is quite prevalent a mistaken idea about santonin which it will be well to uncover before going further. This notion is, that no matter how santonin is given - whether the crystals alone, in powders or solutions - it has invariably the same effect. As a matter of fact this drug as ordinarily administered is dissolved by the gastric juice; and the solution takes place so rapidly that even large doses are generally absorbed in the stomach and do not enter the intestines, the habitat of the worms. Obviously, therefore, it should not be given in powder, for much, if not all, of it would be taken up in the circulation, and failing to reach the worms - turning out of its course as it were to avoid them - its vermicidal effects would be largely, if not entirely, wasted. Moreover, by this rapid absorption its constitutional and poisonous effect upon the patient would be greatly intensified. And here appears the reason why santonin in the hands of some is singularly prone to cause convulsions in puppies.

In order to reduce to the utmost the liability of this accident, also that the santonin may reach the worms, it must be administered in some agent which will practically float it through the stomach and keep it intact until it gets into the intestines where the worms are located. Water certainly will not serve the purpose, for it has been shown by experiments that santonin crystals floating in it will not affect worms. They are killed, however, when brought in contact with an oily solution; and, besides, such solution is not absorbed by the stomach.

Consequently this drug should invariably be given in a fat or an oil, and preferably castor oil; which must not, however, be in too large quantity, because if the santonin is rushed, as it were, too quickly through the intestinal canal it does not have time to produce the desired effect.